Qanat | one of the oldest systems of water supply in the world


Digging aqueduct has been one of the first human technologies, for conduction groundwater to earth surface and cities.

The journey has been always overflowed of great opportunities to watch and experience. One of the advantages of trip is that it rarely gets platitudinous. no matter how much you have traveled, even to repeated destinations and how much experienced you are, it seems the unending desire to go, watch and explore would not subside. It resembles the leader of an orchestra who arranges the musical instruments carefully and writes and tunes the notes very accurately. As a matter of fact, he employs any opportunity to amaze the audience. It does not matter for him, you are a beginner or a journeyman, experienced or inexperienced, adventurer or a tour leader, a journey passionate or running out of routines. anyhow, he is adept in his profession and knows how to involve your mind toward himself. every corner of this territory is full of characteristics which observing them leads to feed honor with all-out, blood boil and patriotism bustle.

It can be found from the stories, fables and the geography of this territory, since the natives of Iran dwelled in this land, the issue of preparing water, has been important as the second main element after fire, beside Tishtrya and Goddess.most numerous civilizations, cities, castles, worship houses, palaces and temples had been constructed near riverbanks, ashore or any sources of water. For many years, people had been influenced by the nature, but they gradually learned how to conquer it. however, there has been always a permanent war for the power between the human and nature. In the meantime, the mankind has gained a huge profit.

One of the elite cases about the preferences of human ability ahead of nature is hydro structures. They include a variety of structures such as Shushtar waterfalls, dikes, dams, and subterranean canal, each of which prove the knowledge and domination of our ancestors in the field of water engineering and their awareness about the importance of water.

Their proficiency about building aqueducts was far better than others. As Bastani Prizi declares, digging and aqueduct was not only an activity to find water, but also it was like a great epic of replacing water with survival and existence.
The origin of the word aqueduct is ghanat, an arabic word meaning spear, which has been gradually translated as canal.

It has also been translated as Qano in Akkadian and Assyrian languages, as well as Ghana or Ghanoin in Hebrew, and in Latin there is a form of Kana. In the Pahlavi language, the word Kahs was used, the equivalent of which in the Persian language we know today is Kariz or Kahriz, meaning canal.

Historically, it is difficult to say when and from which area, the aqueducts appeared in Iran. Existence of aqueducts in the 5,000-year-old civilization of the burnt city, and the Hegmatane civilization, clearly prove that, aqueducts, and the knowledge of digging them, existed in pre-Achaemenid periods. Evidence demostrates that early Iranian natives, dug underground tunnels in mountainous areas, to use groundwater resources during water shortages which dates back to the first millennium BC.


Over time, the technology of aqueduct excavation has been transferred from Iran to other countries in the world.

Over the years, due to trade, wars and cultural influences, the technology of digging aqueducts and exploiting underground aquifers has spread to neighboring countries and other continents, including Africa and America. however, it has always been pointed out in all eras and their historical manuscripts, that this technology is Iranian.

Some researchers, such as Henry Goebbels, believe that digging aqueduct, was not initially an exploration for water, but a branch of the mining technique. Indeed, facing groundwater aquifers, was a problem for miners, when they were digging mines. For this reason, they were seeking a way to get rid of these troubles, so they got help of aqueducts. Of course, this hypothesis is not very plausible, because the age of aqueducts in some areas of Iran, dates back to before the excavation of mines. Also, Goebbels himself later corrected this hypothesis.

Regarding the mechanism of the aqueduct, it should be said that all aqueducts start from a main well, which is called the mother well. It is connected directly to the groundwater aquifer and is moved to the place of consumption by an underground canal. The canal flows the water using the slope of the ground and the force of gravity.

Each canal includes several vertical wells known as Access Shafts that have openings on the ground and are located at certain distances from each other. Access Shafts were not only used as an entrance for diggers and drilling equipment to get into the aqueduct, but also had other uses. In fact, they were employed for air conditioning in the underground canal, as well as for dredging the aqueduct, repairing, visiting, and maintaining the water canal.

There are two categories of Access Shafts: wet shafts or the wet section of the aqueduct and dry shafts or the dry section of the aqueduct. Wet shafts are vertical wells which are linked directly to the groundwater aquifer, and dry shafts are wells that are linked to the canals. these canals reach to the water collection site, so they connect the dry shafts to the groundwater aquifer.

Among all the vertical wells that an aqueduct can have, one of the wells is called Naran Khoshkan well. The main characteristic of this well is that the end of it reaches the edge of the groundwater aquifer. It is the place where the artificial canal separates from the groundwater aquifer and directs the water to the collection site.eventually, the water canal gets out of a place on the ground near the city or irrigated fields and gardens. The outlet place of the aqueduct water was called Payab or the manifestation of aqueduct. Horanj is a reservoir like a pond that is built to store the water of the aqueduct in, and people use it for water consumption.

Construction of a series of aqueduct, basically begins with finding a location for the mother well. the appropriate place to dig a well, is usually located on the slopes of mountains or areas that have plentiful vegetation (proving the presence of groundwater aquifers). then, it is time to dig an underground canal and vertical shafts. Digging wells(vertical shafts) is carried out in two stages including; digging part of the well on the ground for observing signs of water, and from this point on, the well should be drilled from underground, in fact from the underground canal upwards.

For transferring water, vertical wells must be digged in one direction, to use groundwater flow and the slope of the ground. The length of the underground canal depends on various factors such as soil type, slope, power of water flow, and so on.
The interesting point is that Iran not only has the technology to dig aqueducts, but also the best samples of aqueducts in Iran. For example, the Zarch aqueduct of Yazd is the longest aqueduct in the world, by a length of about 100 km and possesses 2115 vertical shafts. The depth of the mother well in this aqueduct is 85 meters and it has a discharge rate of 25 liters per second. Also, several wells of it are located in the Yazd Grand Mosque.


Zarch aqueduct in Yazd is the longest aqueduct in Iran and the world.


Gonabad Qasbeh aqueduct is the deepest aqueduct in Iran and the world.

Another famous aqueduct in Iran is the Qasbeh Gonabad aqueduct. Locals believe a group of demons and jinn has constructed it. Qasbeh aqueduct is the deepest and oldest aqueduct in the world by the length of more than 33 km. However, what makes this aqueduct special is its great depth by about 300 meters deep. Due to the antiquity almost 2500 and 2700 years ago, drilling such wells are beyond our imagination. That is why there are so many stories and legends about digging and building this aqueduct.

one of the other amazing aqueducts of Iran is MOON two-floor aqueduct in Ardestan, which is the only two-story aqueduct in Iran and the world. Each floor in this aqueduct has its own separate water flow so that the water from one of each floor has no way to the other. In fact, this aqueduct has two parallel channels on top of each other.

The length of MOON two-floor aqueduct of Ardestan is 3.5 to 4 km and the depth of the mother well is 31 meters. The aqueduct has 30 vertical shafts and a discharge rate of 60 liters per second, which supplies drinking water for 200 residents of MOON neighborhood of Ardestan. also, the excavation story of This aqueduct is mixed with legends, so that a group of people, attribute digging this aqueduct to Kaveh Ahangar. However, the topic of aqueducts does not end here. The excavation of any aqueduct deals with a series of structures, such as water clocks, refrigerators, water reservoirs, Payabs, and access shafts.

water clocks are one of the technologies which were applied in the construction of aqueducts. In fact, there had been regulations for the use of aqueducts water. MirAb was a person, who had the responsibility of the aqueduct’s water distribution,and monitoring the consumption of the aqueduct’s water.

By means of water clocks, the MirAbs determined the time and duration of using water for farmers and gardeners. The water clock consisted of two large and small bowls. There was a hole in the small bowl, and the larger bowl was full of water. so, when he put the small one on the other one, water flew from the large bowl into it. It took 7.5 minutes for each small bowl to fill and sink, and by every drowning, they put a stone in the bag. The share of each land was determined by the number of stones the landowner had. After placing the last stone in the bag, the mouth of the water entrance to the ground was closed, and Mirab blew into his trumpet, as a sign of the end of the irrigation time and went to the next garden.


In the past, Mirab has played a key role in the division of aqueduct water among farmers and gardeners.

Payab was a place where the outlet of aqueduct was in and was the site of harvesting the aqueducts water in the city or village, where people could use aqueduct water. Basically, because the Payabs were shady and cool, they were considered a place to sit, talk and sometimes for a nap.

The refrigerator is generally known as a place where snow and ice are stored in the winter so that they can be used in the summer. In areas which there were no snow, on cold nights of the year, aqueduct water was transferred to ponds in the back of the refrigerator to freeze during the night’s cold. before sunrise, they broke it and transported to the refrigerator to be stored for the hot season and water less.


The refrigerator has been one of the most important sources for water storage during summer and water shortage seasons in Iran.

Another structure associated with aqueduct is Ab anbar or water reservoir. it is a place for restoring water. In some areas, part of the aqueduct’s water was sent to the reservoirs to be stored there. In this way, people could use aqueduct water. In addition, during the water less season, the water level in the aqueduct may have dropped, so they could store some of the aqueduct water.


Water Reservoir or Ab Anbar has been one of the sources for water storage in tropical regions in Iran.

Aqueducts are known as one of the green technologies for water harvesting because:

• To some extent, it allows the extraction of groundwater and does not empty the aquifer like a well
• Uses gravitational force and a sloping surface to flow water that does not produce pollution.
• No waste of water. Because the water transmission channel is underground and does not evaporate or penetrate the soil.

In 2016, the United Nations Educational, Scientific and Cultural Organization (UNESCO) registered the Iranian aqueduct as a World Heritage Site. 11 aqueducts in Khorasan, Kerman, Yazd, Isfahan and Markazi are on this list.


Qanat has been registered as the twentieth cultural monument of Iran in the UNESCO World Heritage List.

To read this article in Persian Language Click here .

* Written by  Marjan Ghanavati and Translated by Mohsen .


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